Dynamo-electric machine.



A. H. NEULAND, DYNAMO ELECTRIC MACHINE.

, APPLICATION HLED 3ULY29,1915. 1-,Q33,899, Patented Jul 17, 1917.

, 2 SHEETS-SHEET 1.

IN E 'EN TOR. 726M A. H. NEULAND. DYNAMO ELECTRIC MACHINE. APPLICATION FILED JULY 29, ms.

Patented July 17, 191?.

v 2 SHEETS-SHEET 2 DYNAMO-ELECT Application filed July 29, 191s. Serial To (all 107mm it may concern Be it lrnown that l, inroivs H. Nnnnaizn, a subject of the Czar of Russia, residing at the city 01" New York, in the borough of Man hattan and State or New York, have invented. certain new and useful improvements in Lynanio-Electric Machines, of which the following is a full, clear, and exact deucription.

My invention relates to dynamo-electric machines, and embodiments of my invention are adaptable for use as power transmission device for transmitting power from one rotating element, such as a shaft, to another rotatable element.

@nc object or my invention is to provide simple, reliable and etilcient means for adjusting and regulating the speed and torque of the machine. elnother'ohject is to minimize the iron losses in themachine and obtain a maximum of efficiency when operating at normal speed. Another object is to provide simple and ettlcient means for rerersing the machine. Other objects are simplicity, strengtn and durability 0t construction. Still other objects and ad vantages of invention will appear from the following description.

Embodiments oi? my invention are well adaptable for use both as a starter and as an adjustable speed transmission for automobiles, although it will be readily understood that embodiments oii my invention may he applied to many other uses as power transmission devices, to transmit power from o .e rotatingelement to another.

my former application, Serial 855,873, filed August 8, 191%, l have disclosed and claimed a dynamo-electric machine capable of use either as a power transnitting device or an adjustable speed altering current motor, comprising a rotatable arnature provided with a direct current winding and a commutator", a stationary element concent ic with and surrounding the armature and provided with a polyphase winding connected with stationary polyphase rushes on the commutator; and a rotatable field element comprising a pluralit v' of field poles disposed between the element and the armature, to-

anions 2s. nnnnann, or

Specification otletters Eaten.

3521A; nit-L A a r:

The torque of the driven and low speeds is thei i oeing equal to the sum of the t e armature and fon of ro I of the leads conneo with the stator winding. torque upon the field element at and low speeds exceeds t :V times by reason the excess of ampere turns the stator over 1" armature, a reversal ot the connection tween the stationar brushes ant winding, so as to produce a stator upon the iield elemen to that. of the armature causes the field to rotate in opposition to the armature.

As pointed out in nrv said former application. the potentia. of. the unii ormllv driven :2 armature, which. when used tor automobile transmission. is connected to the unidirectionally rotating" engine. is highest when the isle element at rest and decreases when the field folloi'vs the armature. Furor more, a counter-potential generat d in th windin 's of the stator the I'ieid element 1s at Therefore, an he held element is increase in the speed or accompanied by decreased tential and an increased stator counter ink tential. and the two become equal and current becomes Zero when field elen reaches acertain speed, thus limiting speed irrespective of the load.

There ust be a slip from this critical speed. however, in order that tl armature potential may sutlicientlv predominate and force the requisite current through the wind-- to furnish the field element with the necessary torque.

' in nrv said former device. pluralit steps in the speed of the field 1r driven element o tained by changing the volta' .a'. armature and st; s in series armature poadjustable auto-transformer between the stationary brushes and the stator winding. This regulation of the speed requires a polyphase controlling switch of sufiicient capacity to carry the power current, or, in some cases, a polyphase auto-transformer, while a switch for reversing the power leads is required to reverse the direction of rotation.

In accordance with my present invention, I dispense with the necessity of .switching the power leads, and of using an auto-transformer in reversing or adjusting the speed of the driven field. This invention is characterized by the employment of two fields, one acting on the armature and the other acting on the stator, and, for the purpose of regulating the speed of the machine, my invention comprehends means for varying the strengthof one field relative to that of the other. My invention also includes means for reversing the magnetizing current of one field relative to that of the other in order to reverse the machine.

More specifically, the field member coin prises two sets of independently energized field magnets, oneset being in inductive relation to the armature and the other being in inductive relation to the stator. Preferably, these sets of field magnets are carried upon opposite sides of a rotatable magnetic ring, the ring' having external and internal polar projections arranged in alternate relation to each other and forming the cores of the field magnets. The means for varying the relative field consists of two rheostats disposed in therespective magnetizing circuits, and to reverse ,the relative direction of the magnetizing currents, a pole changer is preferably provided in one of the circuits.

My invention also includes various other features of construction and arrangements and combinations of parts, as will hereinafter more fully appear.

I shall now describe the illustrated embodiment of my invention, and shall thereafter point out my invention in claims.

Figure 1 is a longitudinal central section of a dynamo-electric machine embodying my invention, showing in diagram the magnetizing circuits for the fields;

Fig. 2 is a transverse central section of the same; and I Fig. 3 1s a diagram of the electric circuits of the. illustrated machine.

The illustrated machine comprises a rotative armature member which is the driver and includes a commutator, and an external annular stator and polyphase winding therefor surrounding the armature and including stationary polyphase brushes connected to the winding and engaging the commutator, and a driven rotatable field member between the stator andarmature having two sets-of strengths preferably field coils arranged in inductive relation to the stator and armature, respectively.

The stator-1 is laminated and annular in shape and is carried on the inside of the cylindrical portion 2 of the frame or casing. Suitable longitudinal slots 3 are provided at the inner periphery of the stator for the reception of the polyphase stator winding 4. The armature core 5 is laminated and mounted upon a hub 6 secured to the shaft 7."

The armature winding 8 is embedded in suitable longitudinal slots 9 in the face of the armature core. The commutator 10 is also carried by the shaft 7 and rotates with the armature with which it is electrically connected, as shown. Three slip rings 11 on the shaft 7 are connected to the commutator, as shown in Figs. 2 and 3, and are arranged to be short-circuited through a switch 12. At full speed of the field element the switch 12 is thrown so as to short circuit ried by a steel spider or bracket 18, which is fixed to a sleeve 19 rotatably surrounding one end of the shaft 7 and driven shaft. The ring '17 has six integral radially extending steel poles arranged alternately internally andexternally thereof,

the intermediate portions of the ringforming magnetic yokes connecting the pole faces on one side with the adjacent pole faces onthe other side. The poles extend substancoupled to the tially across't he annular space between thearmature and stator and the yoke portions of the ring 17 connect the inner ends of the three external poles, numbered 20, 20*, and

poles numbered 21", 21 and 21". These two sets of poles form the cores of two sets of field magnets arranged in inductive relation to the stator and armature, respectively. The field coils 20 20"and 20 of the stator or external magnets are wound in a like direction and connected in series, and similarly the field coils 20 21 and 21 of the armature or internalcoils are wound in the same direction and opposite to that of the stator field coils and are connected in series. ,Two pairs of slip rings 20*, 20 and 21 21*, on the sleeve 19 are connected to the respective setsiof field magnets. .The'

' therewith by brushes 20 20 and 21, 21

. 20, with the outer ends of the three internal messes respectively, and leads 23, :24, 25 and 26, respectively. (See Fig. 1). The two fields are thus independently energized, and to vary the relative field strengths rheostats 2'7 and 28 are provided in the respective field circuits, while to reverse the relative direction of the two magnetizing currents, a pole changer is provided in one of the circuits, shown as the stator field circuit.

lVhen the stator and armature fields are equally and oppositely excited, the flux of each adjacent pair of field poles traverses bot-h pole pieces and the connecting portions of the armature and stator, without traversing any of the yoke portions of the ring forming adjacent poles. Upon weakening the current in tla internal or armature field coils, the flux through the armature is decreased while that through the stator is not changed, the difierence between the stator and armature fiuXes tr versing the ring. The stator flux is substantially unafi'ected even. when the armature field is entirely cut ofi, all of the stator flux in that event passing t n'ough the yoke portions er the ring; and when the current in the armature field coils is reversed, the stator field still remains the same, but the yoke portions of the ring then carry both the stator and the armature field fluxes. Therefore, either the armature or the stator field may be varied or reversed without materially atlecting the other.

The armature winding 8 is a' series winding and is wound for Si?! poles. The current generated in the armature is connnutated by the commutator 10 and conducted to the stator windings 4 through the stationary polyphase brushes 14, 15 and 16 and their respective leads as above described. These brushes are so arranged that polyphase currents can be collected from the commutator by rotating the field structure and holding the armature stationary. Assuming the brushes belonging to each phase short-circuited orclosed through a resistance, and the armature field energized and held stationary, rotation of tie armature will induce currents in its windings which will appear as direct currents in the resistances connected to those brushes which ha *e a neutral position with respect to the field poles. The other brushes closed through their respective resistances will. also carry a direct current. but oi? lesser intensity. depending upon the position they occupy on the commutator. lit the field element be released and the armature field be allowed to rotate, it is apparent that this neutral position progresses at a corresponding angular velocity. Under such conoitions, as the neutral position passes the brushes belonging to the various phases, an alternating" polyphasc current is in the resistances connecting them. in the construc- 11 lines) belonging to one phase; t (shown in dot and dash lines) belonging to the second phase; and the coils (shown in dotted lines) belonging to the third phase.

polyphase currents collector th brushes circulate through the taor winding and create a revolving field having the same angular velocity as that of the field member. The brushes are connected to the stator winding so that the flux of the stator current produces a torque upon the stator field which adds itself to that resulting; from t a reaction between tl e armature field a d armature current. The field of the statm' current is right angles the stator field of the field member at standstill ot the fie 7 member, and t'iis quadrature relation remains at all speeds of the field member and maintains a torque as long as the armatiue E. F. predominates over the stator counter E. The direction of rotation of the field member depends upon the relative direction of the magnetizing current of the two fields. H the torque of stator field is in opposition to that of the armature field. the field member will be caused to rotate in the opposite direction to that in whievi it rotates when the two torques are in the same direction. since the torque produced by the stator winding predominates reason oi the large number of ampere turns therein as compared with those of the armature. The only ene required at start by the stator winding to produce this opposing torque, is that which is sutficient to overcome the resistance of the winding. Since the current in the armature to furnish this energy is comparatively small, the ampere turns are proportionately small, consequently. the armature torque is smaller, as above stated. and the torque produced by the stator wind ing predominates. Therefore, the reversal of the pole changer 29 serves to reverse the direction of rotation ot the field member.

The armature being rotated by the prime mover through suitable connection n'ith shaft 7. and the field member being secured to the shait to be driven through suitable connection with the driven shaft 30 which is coupled to the sleeve 19. as shown in Fig. l. the apparatus is started by cutting out all the stator field resistance, thereby produc- 7 all the :inixtuzc pro ducing a weak armature field and generating a small potential in the armature which causes a considerable current to flow through the armature and stator windings due to the stationary stator field and the consequent absence of a counter-potential in the stator winding, the current in the stator windings cooperating with the full strength of the stator field, thereby producing a strong torque on the field member. As the armature field resistance is gradually cut out, the armature potential and current and torque produced thereby and by the increased stator current on the stator field are increased until the armature field attains its full strength and produces maximum torque. lVhen the number of turns in series on the armature and stator is the same,'the driven field member will be able to approximate half the speed of the driving armature, since at this speed, the fields being equal, the counter-potential of the stator will be equal to the potential of the armature. An increase of the driven speed above half is attained by leaving the armaturefield fully excited and weakening the stator field, and when the driven field member approaches the speed of the armature, the stator winding and the stator field may be entirely disconnected and either the slip rings 11 "or the polyphase commutator brushes be short-circuited.

As above stated, this apparatus is suitable for use as a transmission for automobiles,

and when so embodied, it may also be used as a starter for the internal combustion engine, operating as a direct current motor. For this purpose, a direct current is made to traverse the stator field and part of the stator winding, whereupon the stator becomes polarized and the field member imme diately assumes its proper position and locks itself relative to the stator. A direct current is introduced into a pair of brushes having proper relation to the field which will rotate the armature and thus start the engine.

The circuits and switching mechanism for thus utilizing the apparatus, are illustrated diagrammatically in Fig. 3. Three contact blades 31, 31 and 31 of a double-throw switch are connected into the three leads 14c, 15 and 16, respectively, of the brushes 14, 15, 16, the contact blades 31" and 31 cooperating with battery contacts 31 and 31, and the contact blade 31 co6perating with the stationary contact 31, in the lead 16. In starting position, switch 31 is thrown to close the battery contacts, which 'movement opens the lead 16 at contact 31" and thus disconnects the brush 16 with the stator coils 4?. This is the position of the switch shown in Fig. 3, and the armature and two phases of the stator windings are energized. as follows: from battery 22 through lead 32, stationary contact 31, movable contact 31" messes to the lead 15, whence the current divides, one portion going to the brush 15, thence through the armature winding, brush 1%, lead 14, movable contact 31, stationary contact 31, leads 33, 24 and 26 back to the battery; and the other portion going through the other part of lead 15, coils 4, thence through coils l and lead 14 back to the'battery as before. The movement of the rheostat con tact lever 34 one step to the right from the open position shown, closes the battery contact with the two fields. The armature field coils 21 21 and 21, which are connected to the slip ring 21 and 21 are energized as follows: from the right side of the battery 22 through the lead 25, rheostat 27 lead 25, brush 21, slip ring 21 armature field coils, slip ring 21, brush 21 and lead 26 back to the battery. The stator, field coils 20, 20"

and 20, which are connected to the slip rings 20 and 20, are energized as follows: from battery 22 through leads 25 and 23, rheostat 28, lead 23, contact of pole changer '29, lead at to brush 20 thence through the slip rings and'coils to brush. 20, thence through lead 23", contact of pole changer 29, and lead 24:, back to the battery.

After the engine is started, the switch 31 is thrown to its other position, which closes the connection between the movable contact 31 and the stationary contact 31 and at the same time disconnects the battery sup ply from the leads 14 and 15. The three brushes 14, 15 and 16 are now connected to I the three phases of the stator winding and the device is ready for use for power transmission.

As previously stated, in starting the device to transmit power from the driving shaft 7 :to the driven shaft 30, the stator field resistance is cut out while the armature field resistance is in. This is the condition when the rheostat contact lever 34 occupies the position one step to the right of that shown in Fig. 3. The rotation of the armature generates a small potential, but the current in the stator windings caused to flow by this potential is considerable, due to the absence of any counterpotential, and the current in the stator windings cooperates with the full strength of the stator field and creates a strong torque on the field member. The armature resistance is now gradually cut out by movin the contact lever 34 step by step to the right until at the intermediate position of. the contact lever 34: the armature field has its full strength and produces maximum torque. At this point, if the number of turns in series on the armature and stator is the same, the counter-potential of the stator winding will equal the armature potential and the driven field member will havea speed approximately one halfthat of the drivnig armature. To increase this relative speed of the driven field meinber, contact lever 3% is moved step by step to the right, which leaves the armature field fully excited and inserts more and more resistance into the stator field. There are as many steps or speed adjustments as there are contact points in the rheostat, and when the driven field member has attained a speed so near to that oi the armature as toelloW only for the slip necessary to induce the required potential, the stator Winding and stator field are entirely disconnected by moving the contact lever 3i the last stop to the right which is elec rically cisconnected. It will be observed that the iron losses in the stator are thereby substantially eliminated and the only iron loss in the apparatus is due to the low armature frequency caused by the slip oi the field. it will also be observed that this construction offers the advantage of nanipulating the comparatively small field currents instead of the polyphase power current, as is the case in the construction described in my aforesaid prior application. Furthermore, this invention provides for a simple and strong revolving field structure, as co pared with my said former construction. In that device the adjoining poles of opposite polarity and also the two pole faces of each pole are bridged or connected by the supper-thi spider, hence it is necessary in that construction to use a spider or 1 .agnetic material, such as alumiu in or Such a field structure is necessarily w eak and consists of many parts, and hence cannot be run at very high spec ls. In the Inesent construction, however, due to the peculiar ar angement of poles and connecting yokes, the entire field structure may be cast in one piece and the supporting spider 18 may also he of steel, since only such pole faces are joined thereby as are of the same polarity. The structure is thereby rendered much stronger as well as more economical and simpler of manufacture.

It is olovious that various nodiiications may be made in the construction shown in 'the drawings and above particularly described, within the principle and scope of my invention.

l. A dynamo-electric machine comprising an armature and a winding therefor, a stator, a winding for the stator, two magnetic fields, one arranged in inductive rela tion to toe armature winding and the other arranged in inductive relation to the stator winding, and means for independently energ'izing the two fields.

:2. A dynamo-electric machine compris ing an armature and a winding therefor, a stator, a winding for the stator, means for connecting the armature winding with the stator winding, two magnetic fields, one arranged in inductive relation to the winding and the other arranged in i live relation he tor windi 1,0 c means for independently I fields.

J o. A. dynamo-electric mac ine co ing an armature and a winding ther stator, a winding for the stator, r

in inductive relation. stator and means for varying the rela strength or the two components.

c an armature ant a winding therefor, a stator. a winding for the stator, a rot field member having an armature held component arranged in inductive relation to the armature winding and a stator lield compo nent arranged in inductive relation to the stator winding. means varying the relativefi'eld strength. of the two con'iponents, and means for reversing the polarity of one field component relative to or the other field component.

dynamo-electric machine comprising an armature and a winding therefor, stator, a winding for the stator, n cans for connecting the armature winding with the stator winding. :1 rotative field member having an armature lield component arranged in iinluctive relation to the armature winding and a stator field. compo; cnt arranged in inductive relation to the stator winding, means for varying of the two comgon versing the polarity of one field cc relative to that the other field component.

'5. in a dynamo-electric machine. a field member having a pli .lity of pole on one side and a plurality of pole faces on another side thereof. a magnetizing coil for each of it pole faces. and a plurality of magnetic yokes connecting the. pole faces on one side with the adjacent pole faces on the other side. said yokes serving to conduct the difference between the tluxc on one side and the fluxes on the other side when the two are unequal but unidirectioiml and serving to carry the sum of the fluxes when the two are opposed.

8. ln a dynamoelectric machine, a field o. A. (lynanio-ele tric machine comprising member having a plurality of internal and a plurality of external pole faces arranged.

in alternate relation, and a plurality of magnetic yokes connecting the alternate external pole faces with the intermediate lnternal pole faces and serving to conduct the differ- I 'the strength and polarity of the magnetizing conduct the difi'erence on one'side relative to that for the coils on the other side, and a plurality of magnetic yokes connecting the pole faces on one side with the adjacent pole faces on the other side, said yokes serving to between the fluxes on one side and the fluxes on the other side when the two are unequal but unidirectional and serving to carry the sum of the fluxes when the two are opposed. 4

10. In a dynamo-electric machine, a field member having a plurality of internal and a plurality of external pole faces, means for producing a flux at the pole faces and for varying the strength and .changing the polarity of the flux at the internal pole faces current for the coils relative to the flux at the outer'pole faces,

and a plurality of magnetic yokes connecting the alternate external pole faces with the intermediate internal pole faces and serving to conduct the difference between the external and internal fluxes when the two are unequal but unidirectional and serving to carry the sum of the external and iiiternal fluxes when they are opposed.

11. In a dynamo-electric machine, in combination, a stator and awinding therefor, a concentric rotatable armature and a winding therefor; a rotative field member comprising a carrying ring disposed between the stator and armature, armature field magnets carried by the ring in inductive relation to the armature, and stator field magnets carried by the ring in inductive relation to the stator; and means for changing the relative strength and polarity of the two fields.

12. In a dyn mo-electric machine, in combination, a stator and a winding therefor, a concentric rotatable armature, awinding therefor, a rotatable field member comprising a magnetic ring disposed between the stator and armature and two sets of field coils carried thereby on opposite sides thereof, the coils of the two sets being arranged alternately about the ring, thereby forming a stator field and an armature field, and

means for changing the relative strength and polarity of the two fields.

13. In a dynamo-electric machlne, in combination, a stator and a winding therefor, a concentric rotatable armature and a winding therefor, means for connecting the armature winding with the stator winding, a 1'0- tative field member comprising a carrying ring disposed between the stator and armature,-armature field magnets carried by the ring in inductive relation to the armature, and stator field magnets earned by thering in inductive relation to the stator; and

means for changing the relative strength and polarity of the two fields.

14. In a dynamo-electric machine,'in combination, a stator and a winding therefor, a concentric rotatable armature, a winding therefor, winding with the stator winding; a rotatable field member comprising a magnetic ring disposed between the stator and armature and two sets of field coils carried thereby on opposite sides thereof, the coils of the two sets being arranged alternately about the ring, thereby forming a stator field and an armature field; and means for changing the relative strength and polarity of the stator and armature fields.

15. In a dynamo-electric machine, in combination, a stator and a winding therefor, a concentric rotatable armature and a winding therefor; a rotatable field member disposed between the stator and armature comrisin a ma etic rin havin alternatel arranged internal and external polar promeans for connecting the armature jections, and "independent field windings,

upon the two sets of projections, forming a stator field in inductive to the stator windin and an armature field in inductive relation to the armature winding; and means for independently energizing and relatively reversing the two fields.

16. In a dynamo-electric machine, in combination, a stator and a winding therefor, a concentric rotatable armature and a winding therefor, means for connecting the armature winding with the stator winding a rotatable field member disposed between the stator and, armature comprising a magnetic ring having alternately arranged internal and external polar projections, and independent field windings upon the two sets of projections, thereby forming a stator field in inductive relation to the stator winding and an armature field in inductive relation to the armature winding; and means for independently energizingthe two fields.

17. In a dynamo-electric machine, in combination, a stator and a winding therefor, a concentric rotatable armature and a winding therefor; a rotative field member comprising a carrying ring disposed between the stator and "armature, armature field inag nets carried by the ring in inductive relation to the armature, and stator field magnets carried by the ring in inductive relation to the stator; means for supplying thereby relation magnetizing current independently to the two fields, and means for reversing the curin one relative to that in the other field relative to in the other 0;, field m 19. 11 dynamic-electric machine, in comhination a stator and winding therefor, conce .lC rotatable armature and a windtherefor, means for connecting the r ure winding with the stator winding; d member disposed etween or and armature comprising a imagharing alternately arranged inexternal polar projections, and it field windings upon the two ejections thereby forming a stator native relation to the stator win darmature field in inductive relai t arliature winding; means for N inclepennentlv energizing the two nelds. and W me ns -r'or reversing the current in one field relative to that in the other field.

- in a dynamo-electric machine, in comvion, a rotatable current generating elecnt, a stationary element including a mg arranged to consume the current generd in the generating element, a rotatable ments and having two sets of field magnets, set being disposed in inductive relation ti each element, and means for changing the elative strength and polarity of the twofiel d magnets.

21. in a dynamo-electric machine, in combination, rotatable current generating elemen t, a stationary element including a wind- -ange to consume the current generated in the generating element; a rotatable field member disposed between the two elements comprising a. magnetic ring having alternately arranged internal and external polar projections, and independent field windings upon the two sets of projections, thereby forming two fields in inductive relation to thc respective elements; and means 1' r indcpendentlv energizing the two fields.

'c, in a dynamo-electric machine, incomation, a rotatable current generating element, a stationary element including a wind- 55, inc; an'anged to consume the current generis, and means for reversing the cur--= windeld member disposed between the two elestator and armature compri and external polar ated in the generating element, niea transferring current between said including a commutator and stat brushes. a rotatable field member di between the two elements and havii o oi field magnets, one beingdi posed in inductive relation to a source or magnetizing current i fields, and means for controllin tive strength of t ie two field In 5 (lynamO-QleCE-liC n bination, le current generatin meat, a stl'il'ionary element inchn. n a v arra' to consume the on; nt gen transicrring curr netic ring having alterno' ternal and enter al polar independent field r 1 sets of projections, thereby 'rorming t fields in inductive relation the resn ,ctire elements; and means for control ln he r-aa- 93,

tive strength and polarity of the wo nelds,

In a dynamo-ole ic machine, a and polyphase *inding' therefor, a armature and winding therefor, table field member disposed stator and armature and hav of field magnets, one set hei b ,7 inductive relation to the stator w! ung' ano the other set being arranged in indu relation to the. armature windin mea its 101 independently energizing the two fields, and means for supplying current to the armature winding and to the stator windi: In a dynamo-electric machine, and a-polyphase iding therefor, i armature and a winding therefor; a

table field member dispos between the magnetic pendent field *indin '1 projections, thereby to inductive relation to the s armature windings, respectively; means for independently energizing the two i'ielc and me for supplying current to the ar ing and to the stator wrnd 26. in a dynamo-electric machine, armature and a winding therefor, a stator r l a polyphase winding there o for the armature, i l. ,c brushes engaging the comnut tor and connected to tie polyphase stator .f rotatable member disposed bet n g e armature and stator, and two independently controlled fields arranged in inductive relation to the stator and armature windings, respectively, and carried by the rotatable memoer.

ll-l. a dynamo-electric machine, an 13 rino: having alternate v 8 1.23s,se9

nected to the polyphase stator Winding, a ..rotatable member disposed between the armature and stator, and two independently energizable sets of field magnets carried by the rotatable member, one set being ar- Copies of this patent may be obtained for five cents each, by addressing the Commission Washington, D. C.

'anged in inductive relation to the armature 9 winding and theother set in inductive relation to the stator winding. In witness whereof, I subscribe my signa ture, in the presence of two Witnesses ALFONS H. NEULAND. Vitnesses:

' VICTOR D. BORST,

. VVALDO M. CHAPIN.

er of Patents. 

